Metal surface coating composition and terminal fitted electric wire

ABSTRACT

A metal surface coating composition and a terminal-fitted electric wire which is anti-corrosion treated with the composition are provided. The composition includes a high-consistency material containing a lubricant base oil and an amide compound, a composition of a phosphorus compound containing one or more compounds represented by the below formulae and a metal, and a nucleating agent: 
     
       
         
         
             
             
         
       
     
     where X 1  to X 7  each represent an oxygen atom or a sulfur atom, R 11  to R 13  each represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, among which at least one is a hydrocarbon group having 1 to 30 carbon atoms, and R 14  to R 16  each represent a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms among which at least one is a hydrocarbon group having 1 to 30 carbon atoms.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of Japanese patent application JP2015-118415 filed on Jun. 11, 2015, the entire contents of which are incorporated herein.

TECHNICAL FIELD

The present application relates to a metal surface coating composition and a terminal fitted electric wire and, more specifically, to a metal surface coating composition excellent in coating property and a terminal fitted electric wire which is anti-corrosion treated with the metal surface coating composition.

BACKGROUND ART

In metal equipment and metal parts, grease is used for the purpose of lubrication and corrosion resistance. For example, Patent Literature 1 (JP4811408B) describes the use of grease containing a perfluoroether base oil, a consistency improver, barium sulfate, or antimony oxide to machinery parts.

SUMMARY

When a surface coating agent such as grease is coated on a metal surface, uniform coating is required.

It is an object of the present application to provide a metal surface coating composition excellent in coating property and a terminal-fitted electric wire improved in corrosion resistance by using the composition.

In order to solve the foregoing problem, the metal surface coating composition according to the present application contains a high-consistency material containing a lubricant base oil and an amide compound, a composition of a phosphorus compound containing one or more compounds represented by the general formulae (1) and (2) and a metal, and a nucleating agent,

where X¹ to X⁷ each represent independently an oxygen atom or a sulfur atom, R¹¹ to R¹³ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, among which at least one is a hydrocarbon group having 1 to 30 carbon atoms, and R¹⁴ to R¹⁶ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atom among which at least one is a hydrocarbon group having 1 to 30 carbon atoms.

The nucleating agent preferably contains an inorganic particle containing a silicate or magnesia. The nucleating agent preferably contains at least one of talc, kaolinite, montmorillonite, and magnesium oxide. The nucleating agent preferably has an average particle diameter of 20 μm or smaller. The nucleating agent is preferably contained at a content of 0.01 to 15 mass parts with respect to 100 mass parts of the total of the ingredients in the metal surface coating composition except the nucleating agent.

The composition of the phosphorus compound and the metal is preferably made of at least one of a metal hydroxide and a metal carboxylate and the phosphorus compound. The metal carboxylate is preferably a metal salicylate.

The amide compound preferably contains one or more compounds represented by the following general formulae (3) to (5):

[Chem. 3]

R21-CO—NH—R22  (3)

[Chem. 4]

R23-CO—NH—Y31-NH—CO—R24  (4)

[Chem. 5]

R25-NH—CO—Y32-CO—NH—R26  (5)

where R21 to R26 each represent independently a saturated or unsaturated linear hydrocarbon group having 5 to 25 carbon atoms, R22 may be hydrogen, and Y31 and Y32 represent a divalent hydrocarbon group having 1 to 10 carbon atoms selected from an alkylene group and a phenylene group having 1 to 10 carbon atoms, or an alkylphenylene group having 7 to 10 carbon atoms.

The amide compound is preferably a fatty acid amide having a melting point within a range of 20° C. to 200° C.

The phosphorus compound preferably has one or more branched linear structures or one or more carbon-carbon double bond structures in the structure of the hydrocarbon groups having 1 to 30 carbon atoms.

The metal forming the composition together with the phosphorus compound is preferably at least one selected from alkali metals, alkaline earth metals, aluminum, titanium, and zinc.

The mass ratio of the total of the lubricant base oil and the amide compound to the composition of the phosphorus compound and the metal is preferably within a range of 98:2 to 30:70.

Then, a terminal-fitted electric wire according to the present application has a feature in that an electric connection part between a terminal and an electric conductor is covered with the metal surface coating composition.

Since the metal surface coating composition according to the present application includes the high-consistency material containing the lubricating base oil and the amide compound, the composition of the specified phosphorus compound and the metal, and the nucleating agent, the composition can be coated uniformly on the metal surface and is excellent in coating property.

Further, in the terminal-fitted electric wire according to the present application, since the electric connection part between the terminal and the electric wire conductor is covered with the metal surface coating composition, stable corrosion resistance can be provided for a long time.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a terminal-fitted electric wire according to a preferred embodiment.

FIG. 2 is a longitudinal cross sectional view along line A-A in FIG. 1.

DESCRIPTION OF EMBODIMENTS

Next, a preferred embodiment of the present application is to be described specifically.

The metal surface coating composition according to the present invention (hereinafter sometimes referred to as the present composition) includes a high-consistency material containing a lubricant base oil and an amide compound, a composition of a specified phosphorus compound and a metal, and a nucleating agent.

The lubricant base oil usable herein includes one of an arbitrary mineral oil, a wax isomerized oil, and a synthetic oil or a mixture of two or more of them used as usual lubricant base oils. The mineral oil usable herein are specifically paraffinic and naphthenic oils, and n-paraffin, which are purified from lubricant fractions contained by distillation under ordinary pressure or distillation under reduced pressure of crude oils by appropriately combining purification treatments such as solvent deasphaltation, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid cleaning, and white clay treatment of a lubricant oil fractions.

The wax isomerized oils usable herein include those prepared through a hydrogen isomerization treatment of a wax raw material, such as natural wax, e.g., petroleum slack wax obtained through solvent dewaxing of a hydrocarbon oil, or a synthetic wax formed by the so-called Fischer Tropsch synthetic process, in which a mixture of carbon monoxide and hydrogen is brought in contact with a suitable synthetic catalyst at a high temperature and a high pressure. In a case of using the slack wax as the wax raw material, since the slack wax contains large amounts of sulfur and nitrogen, which are unnecessary in the lubricant base oil, it is desirable that the slack wax is hydrogenated as needed to prepare and use the wax having been reduced in the sulfur content and the nitrogen content, which is thus used as a raw material.

The synthetic oil is not particularly limited, and includes, for example, a poly-α-olefin, such as a 1-octene oligomer, 1-decene oligomer, and ethylene-propylene oligomer or a hydrogenated product thereof, isobutene oligomer and hydrogenated products thereof, isoparaffin, alkylbenzene, alkylnaphthalene, diester (for example, ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, and di-2-ethylhexyl sebacate), polyol ester (for example, trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate), polyoxyalkylene glycol, dialkyl diphenyl ether, polyphenyl ether, etc.

The kinematic viscosity of the lubricant base oil is not particularly limited. Usually, it is preferably from 1 to 150 mm²/s at 100° C. The kinematic viscosity at 100° C. is more preferably within a range of 2 to 120 mm²/s because the volatility and the handleability in production are excellent. The kinematic viscosity is measured according to JIS K 2283.

The amide compound forms a network structure by hydrogen bonds in the lubricant base oil. This provides the lubricant base oil with the consistency to form a grease-like high-consistency material. That is, when it is used together with the lubricant base oil, a gel-like product is formed at a normal temperature. That is, amide compound gels (semi-solidifies) the liquid lubricant base oil at a normal temperature. The high-consistency material is maintained due to its consistency on the coat surface of the material to be coated at a normal or heat temperature.

The amide compound is a compound having one or more amide groups (—NH—CO—), and a mono-amide compound having one amide group or a bis-amide compound having two amide groups can be used preferably.

Compounds, for example, represented by the following general formulae (3) to (5) can be used as the amide compound. They may be used alone or two or more of them may be used in combination.

[Chem. 3]

R²¹—CO—NH—R²²  (3)

[Chem. 4]

R²³—CO—NH—Y³¹—NH—CO—R²⁴  (4)

[Chem. 5]

R²⁵—NH—CO—Y³²—CO—NH—R²⁶  (5)

In the general formulae (3) to (5), R²¹ to R²⁶ each represent independently a saturated or unsaturated linear hydrocarbon group having 5 to 25 carbon atoms, provided that R²² may be hydrogen; and Y³¹ and Y³² each represent a divalent hydrocarbon group having 1 to 10 carbon atoms selected from an alkylene group and a phenylene group having 1 to 10 carbon atoms, and an alkylphenylene group having 7 to 10 carbon atoms. Further, in the general formulae (3) to (5), hydrogen of the hydrocarbon group constituting R²¹ to R²⁶ may be partially substituted by a hydroxyl group (—OH).

The amide compound represented by the general formula (3) includes, specifically, a saturated fatty acid amide such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide, an unsaturated fatty acid amide such as oleic acid amide and erucic acid amide, and a substituted amide of a saturated or unsaturated long-chain fatty acid and a long-chain amine such as stearylstearic acid amide, oleyloleic acid amide, oleylstearic acid amide, and stearyloleic acid amide. Among them, an amide compound in which at least one of R²¹ to R²² in the general formula (3) is a saturated linear hydrocarbon group having 12 to 20 carbon atoms, for example, an amide compound in which R²¹ is a saturated linear hydrocarbon group having 12 to 20 carbon atoms and R²² is a hydrogen atom in the general formula (3), or an amide compound in which each of R²¹ and R²² in the general formula (3) is saturated linear hydrocarbon group having 12 to 20 carbon atoms is preferred. More specifically, stearylstearic acid amide is preferred.

The amide compound represented by the general formula (4) includes, specifically, ethylene bisstearic acid amide, ethylene bisisostearic acid amide, ethylene bisoleic acid amide, methylene bislauric acid amide, hexamethylene bisoleic acid amide, hexamethylene bishydroxystearic acid amide, and m-xylylene bisstearic acid amide. Among them, an amide compound in which at least one of R²³ and R²⁴ in the general formula (4) is a saturated linear hydrocarbon group having 12 to 20 carbon atoms, for example, an amide compound in which R²³ is a saturated linear hydrocarbon group having 12 to 20 carbon atoms and R²⁴ is a hydrogen atom in the general formula (4), or an amide compound in which each of R²³ and R²⁴ is a saturated linear hydrocarbon group having 12 to 20 carbon atoms in the general formula (4) is preferred. More specifically, ethylene bisisostearic acid amide is preferred.

The amide compound represented by the general formula (5) includes specifically, for example, N,N′-distearyl sebacic acid amide. Among them, an amide compound in which at least one of R²⁵ and R²⁶ in the general formula (5) is a saturated linear hydrocarbon group having 12 to 20 carbon atoms, for example, an amide compound in which R²⁵ is a saturated linear hydrocarbon group having 12 to 20 carbon atoms and R²⁶ is a hydrogen atom in the general formula (5) or an amide compound in which each of R²⁵ and R²⁶ in the general formula (5) is a saturated linear hydrocarbon group having 12 to 20 carbon atoms is preferred.

From a viewpoint of tending to keep a gel state (semi-solid state) at a normal temperature when mixed with a lubricant base oil or tending to keep a gel-state (semi-solid state), the amide compound preferably has a melting point of 20° C. or higher. It is more preferably 50° C. or higher, even more preferably 80° C. or higher, and particularly preferably 120° C. or higher. Further, the melting point is preferably 200° C. or lower, more preferably 180° C. or lower, even more preferably 150° C. or lower. Further, the molecular weight of the amide compound is preferably within a range of 100 to 1000, and more preferably within a range of 150 to 800.

From a viewpoint of tending to keep the gel-state (semi-solid state) at a normal temperature when mixed with the lubricant base oil and tending to keep a gel state (semi-solid state) at a normal temperature, the content of the amide compound is preferably 1 mass part or more with respect to 100 mass parts of the lubricant base oil. It is more preferably 2 mass parts or more, and even more preferably 5 mass parts or more. Further, it is preferably 70 mass parts or less, more preferably 60 mass parts or less, and even more preferably 50 mass parts or less with respect to 100 mass parts of the lubricant base oil. Preferably, it is 60 mass parts or less, and more preferably 50 mass parts or less.

A specified phosphorus compound contains one or more compounds represented by the following general formulae (1) and (2):

where X¹ to X⁷ each represent independently an oxygen atom or a sulfur atom, R¹¹ to R¹³ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms and at least one of them is a hydrocarbon group having 1 to 30 of carbon atoms, R¹⁴ to R¹⁶ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atom and at least one of them is a hydrocarbon group having 1 to 30 carbon atoms.

The hydrocarbon group includes, for example, alkyl group, cycloalkyl group, alkyl-substituted cycloalkyl group, alkenyl group, aryl group, alkyl-substituted aryl group, and aryl alkyl group.

The alkyl group includes, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group. They may be either linear or branched.

The cycloalkyl group includes, for example, cyclopentyl group, cyclohexyl group, and cycloheptyl group. The alkyl-substituted cycloalkyl group includes, for example, methylcyclopentyl group, dimethylcyclopentyl group, methylethylcyclopentyl group, diethylcyclopentyl group, methylcyclohexyl group, diethylcyclohexyl group, methylethylcyclohexyl group, diethylcyclohexyl group, methylcycloheptyl group, dimethylcycloheptyl group, methylethylcyclopeptyl group, and diethylcycloheptyl group. The substitution position of the alkyl-substituted cycloalkyl group is not particularly restricted. The alkyl group may be linear or branched.

The alkenyl group includes, for example, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, and octadecenyl group. They may be either linear or branched.

The aryl group includes, for example, phenyl group, and naphthyl group. Alkyl-substituted aryl group includes, for example, tolyl group, xylyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, undecylphenyl group and dodecylphenyl group. The substitution position of the alkyl substituted aryl group is not particularly restricted. The alkyl group may be linear or branched. The arylalkyl group includes, for example, benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, phenylpengyl group, and phenylhexyl group. The alkyl group may be linear or branched.

All of X¹ to X⁷ are preferably oxygen atoms. The hydrocarbon group of R¹¹ to R¹⁶ having 1 to 30 carbon atoms are preferably hydrocarbon groups having 4 to 30 carbon atoms, and more preferably hydrocarbon groups having 8 to 30 carbon atoms.

Preferably, all of X¹ to X⁷ are oxygen atoms. Preferably, at least one of R¹¹ to R¹³ is a hydrogen atom and at least one of them is a hydrocarbon group having 1 to 30 carbon atoms. Preferably, at least one of R¹⁴ to R¹⁶ is a hydrogen atom and at least one of them is a hydrocarbon group having 1 to 30 carbon atoms.

The phosphorus compound represented by the general formula (1) includes, for example, phosphorous acid, monothiophosphorous acid, dithiophosphorous acid, phosphite monoester, monothiophosphite monoester, dithiophosphite monoester, phosphite diester, monothiophosphite diester, dithiophosphite di ester, phosphite triester, monothiophosphite triester, and dithiophosphite triester. They may be used alone or two or more of them may be used in combination as the phosphorus compounds represented by the general formula (1).

The phosphorus compound represented by the general formula (2) includes, for example, phosphoric acid, monothiophosphoric acid, dithiophosphoric acid, phosphate monoester, monothiophosphate monoester, dithiophosphate monoester, phosphate diester, monothiophosphate diester, dithiophosphate diester, phosphate triester, monothiophosphate triester, and dithiophosphate triester. They may be used alone or two or more of them may be used in combination as the phosphorus compound represented by the general formula (2).

For the phosphorus compound, from a viewpoint of the following compatibility improving effect, stickiness improving effect, adhesion improving effect, etc., the phosphorus compound represented by the general formula (2) is more preferred. Further, among the phosphorus compounds represented by the general formula (2), acidic phosphate ester represented by the following general formula (6) or general formula (7) is particularly preferred.

(Chem. 8)

P(═O)(—OR¹⁴)(—OH)₂  (6)

(Chem. 9)

P(═O)(—OR¹⁴)₂(—OH)  (7)

In the composition of the specified phosphorus compound and the metal, the phosphate group (P—O⁻ group) is also ionically bonded to the coating surface of the material to be coated thereby contributing to firm adhesion of the high-consistency film containing the high-consistency material and the composition of the specified phosphorus compound and the metal to the coating surface. By being formed as the composition together with the metal, the ionic bondability of the phosphate group (P—O⁻ group) is improved to promote ion bonding. Further, by being formed as the composition together with the metal, the composition of the specified phosphorus compound and the metal is made adhesive. Further, composition formed together with the metal lowers the acidity of the specified phosphorus compound (pH increase), thereby suppressing corrosion of the metal surface to be coated with the specified phosphorus compound.

The metal forming the composition with the specified phosphorus compound preferably has 2 or more valence from a viewpoint of heat resistance.

The metal that forms the composition together with the specified phosphorus compound includes, for example, alkali metal such as Li, Na, and K, alkaline earth metal such as Mg and Ca, aluminum, titanium, zinc, etc. They may be used alone or two or more of them may be used in combination. The salts of the metals can provide high adsorption to the metal surface. Further, since the ionization tendency is, for example, higher than that of Sn, it can be excellent in the ion bondability to Sn. Among them, Ca and Mg are more preferred from a viewpoint for example, of waterproofness.

The composition of the specified phosphorus compound and the metal can be formed by mixing a specified phosphorus compound and a metal-containing compound (metal ion supplying source). The metal-containing compound includes metal hydroxides, metal carboxylates, etc. The carboxylic acid of the metal carboxylates includes salicylic acid, benzoic acid, phthalic acid, etc. The metal salt of the carboxylic acid is a neutral salt and, further, may be a basic salt obtained by heating excess metal, metal oxide or metal hydroxide in the presence of water, or may be a super basic salt obtained by reacting metal, metal oxide or metal hydroxide in the presence of gaseous carbon dioxide, boric acid, and borate may be used. Among them, super basic salicylic acid or the like is preferred as the metal-containing compound (metal ion supplying source) from a viewpoint of the solubility and reactivity of metal ions during reaction.

For the composition of the specified phosphorus compound and the metal, a composition previously formed by separately mixing a specified phosphorus compound and a metal-containing compound (metal ion supplying source) may be used, or a composition formed by mixing a specified phosphorus compound and a metal-containing compound (metal ion supplying source) together with a lubricant base oil and an amide compound to form a composition during mixing may also be used. Further, a composition formed by mixing a previously prepared high-consistency material containing a lubricant base oil and an amide compound together with a specified phosphorus compound and a metal-containing compound (metal ion supplying source) may also be used.

From a viewpoint of forming a composition reliably at a desired blending ratio, it is preferable to use a composition formed previously by separately mixing a specified phosphorus compound and a metal-containing compound (metal ion supplying source) as the composition of the specified phosphorus compound and the metal.

In the composition of the specified phosphorus compound and the metal, when at least one of the hydrocarbon group of the specified phosphorus compound is a hydrocarbon group having 4 to 30 carbon atoms, the compatibility with the lubricant base oil, which is the long-chained alkyl compound, is improved. The hydrocarbon group is an organic group containing carbon and hydrogen but not containing hetero elements such as N, O, and S. Then, in view of the compatibility with the lubricant base oil which is the long-chained alkyl compound, the hydrocarbon group of the specified phosphorus compound is preferably an aliphatic hydrocarbon group or a cycloaliphatic hydrocarbon group. More preferably, it is an aliphatic hydrocarbon group.

The aliphatic hydrocarbon group includes alkyl group containing a saturated hydrocarbon and, an alkenyl group containing an unsaturated hydrocarbon, each of which may be used. The alkyl group or the alkenyl group as the aliphatic hydrocarbon group may be either in a linear or branched structure. However, when the alkyl group is a linear alkyl group such as an n-butyl group or n-octyl group, alkyl groups tend to be aligned to each other and increase the crystallinity of the composition of the specified phosphorus compound and the metal, lowering the solubility with the lubricant base oil. In view of the above, when the hydrocarbon group is an alkyl group, a branched alkyl group is more preferred compared to a linear alkyl group. On the other hand, since the alkenyl group has one or more carbon-carbon double bond structures, it has not so-high crystallinity even if it has a linear structure. Accordingly, the alkenyl group may either be linear or branched.

When the number of carbon atoms of at least one hydrocarbon group is less than 4, the specified phosphorus compound becomes inorganic. Further, the specified phosphorus compound tends to increase the crystallinity. Then, it shows poor solubility with the lubricant base oil and is no longer miscible with the lubricant base oil. On the other hand, if the number of carbon atoms of the hydrocarbon group is more than 30, the specified phosphorus compound shows excessively high viscosity and tends to lower the fluidity. The number of carbon atoms of the hydrocarbon group is preferably 5 or more and, more preferably, 6 or more in view of the compatibility with the lubricant base oil. Further, the number of carbon atoms of the hydrocarbon group is preferably 26 or less and, more preferably, 22 or less from a viewpoint of fluidity, etc.

Further, the composition of the specified phosphorus compound and the metal has a phosphate group (polar group) and a non-polar group (hydrocarbon group in the ester portion) together in the molecule, and can be present in a layered state in which polar groups are associated to each other and non-polar groups are associated to each other and, accordingly, the composition can be a highly viscous liquid even in a non-polymerized state. If it is a viscous liquid, the composition can be adhered more intensely to the metal surface by utilizing the physical adsorption due to Van der Waals force. It is considered that the viscosity is obtained by the entanglement caused between linear molecular chains to each other. In view of the above, it is preferred not to promote crystallization of the specified phosphorus compound. Specifically, for this purpose, hydrocarbon group has a number of hydrocarbon from 4 to 30, has one or more branched chain structures or one or more carbon-carbon double bond structures, etc.

From a viewpoint of the adhesion, it is necessary that the specified phosphorus compound forms a composition together with the metal. When the specified phosphorus compound itself which is not composited with the metal is used, the polarity of the phosphate group portion is small, the association between the polar phosphate groups (cohesion property) is low, and a liquid of high viscosity is not formed. Accordingly, adhesion (viscosity) is low. Further, when it is composited with ammonia or amine, the polarity at a portion of the phosphate (amine salt) is small, and the association (cohesion property) between the phosphates (amine salts) which are polar groups to each other is low, failing to form a liquid at high viscosity. Accordingly, the adhesion (viscosity) is low.

The hydrocarbon group includes more specifically, for example, oleyl group, stearyl group, isostearyl group, 2-ethylhexyl group, butyloctyl group, isomyristyl group, isocetyl group, hexyldecyl group, octyldecyl group, octyldodecyl group, and isobehenyl group.

Then, the specific acid phosphate ester includes, for example, butyloctyl acid phosphate, isomyristyl acid phosphate, isocetyl acid phosphate, hexyldecyl acid phosphate, isostearyl acid phosphate, isobehenyl acid phosphate, octyldecyl acid phosphate, octyldodecyl acid phosphate, isobutyl acid phosphate, 2-ethylhexyl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, myristyl acid phosphate, palmityl acid phosphate, di-butyloctyl acid phosphate, di-isomyristyl acid phosphate, di-isocetyl acid phosphate, di-hexyldecyl acid phosphate, di-isostearyl acid phosphate, di-isobehenyl acid phosphate, di-octyldecyl acid phosphate, di-octyldodecyl acid phosphate, di-isobutyl acid phosphate, di-2-ethylhexyl acid phosphate, di-isodecyl acid phosphate, di-tridecyl acid phosphate, di-oleyl acid phosphate, di-myristyl acid phosphate, di-palmityl acid phosphate, etc. Among them, from a viewpoint, for example, of non-crystallinity and molecular chain entanglement with the lubricant base oil, oleyl acid phosphate and isostearyl acid phosphate are preferred.

The molecular weight of the composition of the specified phosphorus compound and the metal is preferably 3,000 or lower because the compatibility with the high-consistency material is improved by fine dispersion. It is more preferably 2,500 or lower. Further, it is preferably 80 or higher, and more preferably 100 or higher from a viewpoint, for example, of separation restriction due to increased concentration of the polar group. The molecular weight can be obtained by calculation. In the following IS-SA-Ca, the molecular weight (weight average molecular weight) is measured by GPC.

In the present composition, providing that a composition of the specified phosphorus compound and the metal is contained, a specified phosphorus compound not composited with the metal may be contained partially. However, if the ratio of the specified phosphorus compound itself increases in the present composition, the ionic bondability is lowered, the adhesion (viscosity) is lowered, and the effect of preventing corrosion is lowered, and therefore, it is preferred that the ratio of the specified phosphorus compound not composited with the metal is smaller.

As an index of measuring the ratio of the specified phosphorus compound itself, there is a method of measuring pH of the present composition. As the ratio of the acid phosphate ester increases, the residual amount of the phosphate group (P—OH group) is increased to increase the acidity (lower the pH). As the ratio of the acid phosphate ester is lowered, the residual amount of the phosphate group (P—OH group) is decreased to lower the acidity (increase pH). The pH of the present composition is preferably 4 or more, and more preferably 5.5 or more.

Further, the ratio (molar ratio) of the specified phosphorus compound and the metal can be shown also by a value f, assuming f=1×x−m×y where the valence number of the specified phosphorus compound is x⁻, the valence number of the metal is y⁻, the mol number of the specified phosphorus compound is 1, and mol number of the metal is m. In the range of f>0, the specified phosphorus compound is excessive to the metal and the phosphate group (P—OH) remains. At f=0, the specified phosphorus compound is equivalent to the metal and the phosphate group (P—OH group) does not remain. Further, in a range of f<0, the specified phosphorus compound is insufficient to the metal and the phosphate group (P—OH group) does not remain. For increasing the pH of the present composition, it is preferred that f≤0.

The mass ratio of the high-consistency material (total of the lubricant base oil and the amide compound) to the composition of the phosphorus compound and the metal is preferably within a range of 98:2 to 30:70. It is more preferably within a range of 95:5 to 40:60. If the ratio of the high-consistency material is more than 98 mass parts, the fluidity is lowered. If the ratio of the high-consistency material is less than 30 mass parts, the consistency of the high-consistency film after coating is lowered.

The nucleating agent promotes crystallization of the amide compound contained in the high-consistency material. In the high-consistency material, the amide compound is mixed with the lubricant base oil and, at a normal temperature, the amide compound forms a polymer by hydrogen bond in the lubricant base oil, and forms an organogel together with the matrix of lubricant base oil to show a grease-like property with high viscosity. Such a high-consistency material melts at not less than a predetermined temperature relating to a melting point of the amide compound and is changed to be the same viscosity as the matrix of lubricant base oil. Such a high-consistency material can be easily used in surface coating by applying it in a state of heated to a temperature not less than the melting point of the amide compound and, subsequently, returning it to a normal temperature. If the temperature during coating or the cooling after coating is not appropriate in the process, phase nonuniformity occurs during cooling to cause cracking in the film, failing to form a uniform film. Particularly, in the composition of improving the heat resistance by using an amide compound of high melting point, since the difference between the temperature during coating and the normal temperature becomes large, nonuniformity tends to become more noticeable. The nucleating agent is added for suppressing such nonuniformity of the phase by promoting the crystallization of the amide compound.

The cracking due to the phase nonuniformity is caused in a composition in which a composition of a specified phosphorus compound and a metal is blended with a high-consistency material. Cracking is not caused after melting and coating for the high-consistency material containing only the lubricant base oil and the amide compound. Accordingly, it is not necessary to blend the nucleating agent, for the purpose of preventing cracking, with the high-consistency material containing the lubricant base oil and the amide compound. However, since the adhesion with the metal surface cannot be ensured only by the high-consistency material containing the lubricant base oil and the amide compound, peeling occurs at the surface of the metal when volumic change (shrinkage) occurs in the high-consistency material upon cooling from the temperature during coating to the normal temperature, thereby making the coated surface nonuniform.

Such a nucleating agent is not particularly limited so long as the agent promotes crystallization of the amide compound, but an inorganic particle containing silicate or magnesia is preferred. The inorganic particle containing the silicate or magnesia includes, for example, talc, kaolinite, montmorillonite, and magnesium oxide. They may be used alone or two or more of them may be used in combination as the nucleating agent. Among the nucleating agents, talc is particularly preferred.

Talc is a layered mineral containing silicic acid, magnesia and water of crystallization, and the lamination surface thereof tends to be peeled. It is supposed that talc tending to form a fresh magnesia portion by peeling tends to act on the amide compound which is highly polar and slightly basic.

The average particle diameter of the nucleating agent is preferably 20 μm or smaller. It is more preferably 15 μm or smaller, and even more preferably 10 μm or smaller. When the particle diameter of the nucleating agent is 20 μm or smaller, agglomeration of particles is suppressed and nonuniformity of the film due to particles is suppressed. Further, an average particle diameter of the nucleating agent is preferably 0.1 μm or larger. It is more preferably 0.5 μm or larger, and even more preferably 1.0 μm or larger. When the particle diameter of the nucleating agent is 0.1 μm or larger, it is excellent in dispersibility to the high-consistency material containing the lubricant base oil and the amide compound and in the handleability. The average particle diameter of the nucleating agent can be measured by a dynamic light scattering method, laser diffraction/scattering method, picture imaging, etc.

The content of the nucleating agent is preferably 0.01 mass parts or more with respect to 100 mass parts of the total of the ingredients in the metal surface coating composition except the nucleating agent. It is more preferably 0.1 mass parts or more, and even more preferably 0.5 mass parts or more. When the content of the nucleating agent is 0.01 mass parts or more, it provides an excellent phase homogenization effect due to crystallization promotion of the amide compound. Further, the content of the nucleating agent is preferably 15 mass parts or less with respect to 100 mass parts of the total of the components except the nucleating agent. It is more preferably 10 mass parts or less, and even more preferably 5.0 mass parts or less. When the content of the nucleating agent is 15 mass parts or less, agglomeration of the particles is suppressed and nonuniformity of the film caused by particles is suppressed.

The specific gravity of the nucleating agent is preferably within a range of 0.5 to 6.0. It is more preferably within a range of 0.7 to 5.0. When the specific gravity of the nucleating agent is within the range of 0.5 to 6.0, precipitation, floating, etc. can be suppressed, dispersibility to the high-consistency material containing the lubricant base oil and the amide compound is excellent, and the effect of phase homogenization due to crystallization promotion of the amide compound is excellent.

In the present composition, an organic solvent, a stabilizer, a corrosion inhibitor, a dye, a viscosity improver, a filler, etc. can be added in addition to the high-consistency material and the composition of the specified phosphorus compound and the metal as long as the function of the present composition is not deteriorated.

The present composition can be obtained by mixing the high-consistency material containing a lubricant base oil and the amide compound, a composition of a specified phosphorus compound and a metal, a nucleating agent, and optionally added components. Further, the present composition can be obtained also by mixing a lubricant base oil, an amide compound, a composition of a specified phosphorus compound and a metal, a nucleating agent, and optionally added components. A high-consistency film is kept at the coated surface after coating due to the consistency of the high-consistency material. When an amide compound of higher melting point is used, viscosity similar to that under a normal temperature is maintained at a high temperature lower than the melting point and the high-consistency film is maintained on the coating surface after coating. The composition of the specified phosphorus compound and the metal acts as a metal adsorption component and contributes to the improvement of the adhesion of the high-consistency film on the metal surface. The present composition can be coated on the surface of the material to be coated by coating the present composition on the surface of the material to be coated, or dipping the material to be coated in the present composition. The nucleating agent suppresses the phase nonuniformity by promoting the crystallization of the molten amide compound. This suppresses cracking of the film to form a uniform film.

The thickness of the high-consistency film coated on the surface of the material to be coated is preferably 100 μm or smaller from a viewpoint of preventing outward flow or preventing leakage from the coated portion. It is more preferably 50 μm or smaller. On the other hand, it is preferably at a predetermined thickness or larger from a viewpoint, for example, of mechanical strength, etc. of the high-consistency film to be coated. The lower limit of the film thickness includes, for example, 0.5 μm, 2 μm, 5 μm, etc.

The present composition can be used, for example, to lubrication or corrosion protection, etc. For use in the corrosion protection, it can be used, for example, as a corrosion inhibitor for a terminal-fitted electric wire.

Next, a terminal-fitted electric wire according to the present application is to be described.

A terminal-fitted electric wire according to the present application is an electric wire in which terminal is connected to the conductor end of the insulation electric wire, and the electric connection portion between the terminal and the electric wire conductor is covered with a high-consistency film including a high-consistency material containing a lubricant base oil and an amide compound, a composition of a specified phosphorus compound and a metal, and a nucleating agent. Thus, corrosion at the electric connection portion is prevented.

FIG. 1 is a perspective view of a terminal-fitted electric wire according to a preferred embodiment of the present application, and FIG. 2 is a vertical cross sectional view along line A-A in FIG. 1. As illustrated in FIG. 1 and FIG. 2, in a terminal-fitted electric wire 1, an electric wire conductor 3 of a covered electric wire 2 covered with an insulation cover (insulator) 4 and a terminal 5 are electrically connected by an electric connection portion 6.

The terminal 5 has a tab-shaped connection part 51 formed by an elongate flat plate to be connected with a mating terminal, and an electric wire fixing portion 54 containing a wire barrel 52 and an insulation barrel 53 formed at the extended end of the connection portion 51. The terminal 5 can be formed (fabricated) to a predetermined shape by pressing a plate material made of a metal.

In the electric connection portion 6, the insulation cover 4 at the end of the covered electric wire 2 is stripped to expose the electric wire conductor 3, and the exposed electric wire conductor 3 is press-bonded to one side of the terminal 5 to connect the covered electric wire 2 with the terminal 5. The wire barrel 52 of the terminal 5 is crimped over the electric wire conductor 3 of the covered electric wire 2 to electrically connect the electric wire conductor 3 with the terminal 5. Further, the insulation barrel 53 of the terminal 5 is crimped over the insulation cover 4 of the covered electric wire 2.

In the terminal-fitted electric wire 1, a range surrounded by a dotted chain is covered with a high-consistency film 7 obtained from the present composition. Specifically, a range from the surface portion of the terminal 5 ahead of the top end of the electric wire conductor 3 partially exposed from the insulation cover 4 to the surface portion of the insulation cover 4 behind the backward end of the electric wire conductor 3 partially exposed from the insulation cover 4 is covered with the high-consistency film 7. That is, on the side of the top end 2 a of the covered electric wire 2, the terminal-fitted electric wire 1 is covered with the high-consistency film 7 in a range that protrudes slightly from the top end of the electric wire conductor 3 to the side of the connection portion 51 of the terminal 5. On the side of the top end 5 a of the terminal 5, the terminal-fitted electric wire 1 is covered with the high-consistency film 7 in a range that protrude slightly from the end of the insulation barrel 53 to the side of the insulation cover 4 of the covered electric wire 2. Then, as shown in FIG. 2, the lateral side 5 b of the terminal 5 is also covered with the high-consistency film 7. The back surface 5 c of the terminal 5 may or may not be covered with the high-consistency film 7. The peripheral end of the high-consistency film 7 contains a portion in contact with the surface of the terminal 5, a portion in contact with the surface of the electric wire conductor 3, and a portion in contact with the surface of the insulation cover 4.

In this way, the electric connection portion 6 is covered with the high-consistency film 7 at a predetermined thickness along the shape of the outer periphery of the terminal 5 and the covered electric wire 2. Thus, a portion of the electric wire 2 from which the electric wire conductor 3 is exposed is completely covered with the high-consistency film 7 so as not to be exposed to the outside. Accordingly, the electric connection portion 6 is completely covered with the high-consistency film 7. Since the high-consistency film 7 has excellent adhesion with all of the electric wire conductor 3, the insulation cover 4, and the terminal 5, the high-consistency film 7 prevents intrusion of moisture, etc. from the outside to the electric wire conductor 3 and the electric connection portion 6, which may corrode the metal portion. Further, since the high-consistency film 7 is excellent in adhesion, a gap is less likely to be formed between the high-consistency film 7 and any of the electric wire conductor 3, the insulation cover 4, and the terminal 5 at the peripheral end of the high-consistency film 7 even when the electric wire is bent, for example, in the process from the production of the wire harness to the attachment to a vehicle, thereby maintaining the waterproofness and corrosion protection function.

The present composition forming the high-consistency film 7 is coated for a predetermined range. For the coating of the present composition forming the high-consistency film 7, known methods such as dripping, coating, etc. can be used.

The high-consistency film 7 is formed at a predetermined thickness for a predetermined range. The thickness is, preferably, within a range of 0.01 to 0.1 mm. If the high-consistency film 7 is excessively thick, it is difficult to insert the terminal 5 into the connector. If the high-consistency film 7 is excessively thin, the corrosion protection function tends to be lowered.

The electric wire conductor 3 of the covered electric wire 2 is a stranded wire composed of a plurality of wires 3 a. In this case, the stranded wire may be composed of a single type of metal wires or two or more types of metal wires. Further, the stranded wire may also be composed of organic fibers in addition to metal wires. The stranded wire composed of a single type of metal wires means that all metal wires forming the stranded wire are formed from the same metal material, while the stranded wire composed of two or more types of metal wires means that the stranded wire contains metal wires formed from different metal materials. The stranded wire may also include reinforcing wires (tension members) for reinforcing the covered electric wire 2.

The material for metal wire forming the electric wire conductor 3 includes, for example, copper, copper alloys, aluminum, aluminum alloys, or materials formed by applying various platings to the materials described above. The material for the metal wire as the reinforcing wires includes, for example, copper alloys, titanium, tungsten, stainless steel, etc. Further, the organic fibers as the reinforcing wire include, for example, KEVLAR. Metal wires forming the electric wire conductor 3 are preferably aluminum, aluminum alloys or materials formed by applying various types of plating to the materials described above from a viewpoint of reducing the weight.

The material for the insulation cover 4 includes, for example, rubber, polyolefin, PVC, thermoplastic elastomer, etc. They may be used alone or two or more of them may be used in combination. Various additives may be added properly to the material of the insulation cover 4. The additives include, for example, flame retardants, fillers, colorants, etc.

The material for the terminal 5 (material for matrix) includes various copper alloys, copper, etc. in addition to generally used brass. The surface of the terminal 5 may be applied with plating of various metals such as tin, nickel, and gold partially (for example, to contacts) or entirely.

While a terminal is press-bonded to the end of the electric wire conductor in the terminal-fitted electric wire 1 illustrated in FIG. 1, other known electric connection methods such as welding may also be used instead of the press-bonding connection.

Example

The present invention is to be described by way of examples but the present invention is not restricted to the examples.

(Preparation of High-Consistency Material)

High-consistency materials were prepared by mixing lubricant base oils and amide compounds according to blending compositions (parts by mass) shown in Tables 1 and 2.

-   -   Lubricant base oil A: Mineral type base oil (kinematic         viscosity=4.0 mm²/s (100° C.))     -   Lubricant base oil B: Mineral type base oil (kinematic         viscosity=11.1 mm²/s (100° C.))     -   Lubricant base oil C: Synthetic type base oil (kinematic         viscosity=100.0 mm²/s (100° C.))     -   Amide compound A: Ethylene bisstearylamide “SLIPACKS E” (melting         point 150° C., molecular weight 592) manufactured by Nippon         Kasei Chemical Co. Ltd.     -   Amide compound B: Ethylene biserucic acid amide “SLIPACKS R”         (melting point 120° C., molecular weight 700) manufactured by         Nippon Kasei Chemical Co. Ltd.

(Preparation of Composition of Phosphorus Compound and Metal) <Preparation Example 1> OL-Ca

Into a 500 mL flask, 50 g (acid value 0.163 mol) of oleyl acid phosphate (“Phoslex A18D” manufactured by SC Organic Chemical Co., Ltd., molecular weight 467 (average), acid value 183 mgKOH/g) and 50 mL of methanol were added and stirred at 50° C. to form a uniform solution. 6.04 g (0.0815 mol) of calcium hydroxide was added therein. The liquid suspension was stirred for 24 hours at a room temperature and after confirming that the precipitates of calcium hydroxide disappeared, it was filtered and methanol and formed water were distilled off under a reduced pressure by a rotary evaporator. Then, after adding 50 mL of toluene, the formed water was distilled off by azeotropy through vacuum distillation to obtain a clear and viscous aimed product.

<Preparation Example 2> IS-Ca

An aimed clear viscous product was obtained in the same manner as in Preparation Example 1 except for using 50 g (acid value 0.159 mol) of isostearyl acid phosphate (“Phoslex A18OL” manufactured by SC Organic Chemical Co., Ltd., molecular weight 487 (average), acid value 178 mgKOH/g) instead of oleyl acid phosphate and changing the amount of calcium hydroxide added thereto to 5.89 g (0.0795 mol).

<Preparation Example 3> IS-SA-Ca

An aimed viscous brown product was obtained by charging, into a 500 mL flask, 100 g (acid value 0.317 mol) of isostearyl acid phosphate (“Phoslex A18OL” manufactured by SC Organic Chemical Co., Ltd., molecular weight 487 (average), acid value 178 mgKOH/g) and 116 g of super basic calcium alkyl salicylate (Ca content: 8.0 mass %, super basic Ca content: 5.5 mass %) (super basic Ca mass 6.4 g=0.159 mol), stirring it at 120° C. for 3 hours and then cooling it to a room temperature.

(Preparation of Metal Surface Coating Composition)

A metal surface coating composition was prepared by mixing a composition of each phosphorus compound and metal, a high-consistency material, and a nucleating agent each at a predetermined ratio (parts by mass) under heating at 160° C.

Nucleating Agent

Talc: [D-1000] manufactured by Nippon Talc Co., Ltd. (average grain size 1.0 μm), [SG-95] (average grain size 2.5 μm) and [K−1] (average grain size 8.0 μm),

Kaolinite: “Glomax LL” manufactured by TAKEHARA KAGAKU KOGYO CO., LTD. (average grain size 1.5 μm)

Montmorillonite: [SE-3010] manufactured by Sud-Chemie (average grain size 0.3 μm)

Magnesium oxide: Reagent (average grain size 10 μm)

The average grain size of the nucleating agent was measured by a laser diffraction type grain size distribution measuring apparatus.

<Evaluation for Coating Property>

After immersing a copper plate for 20 seconds in a metal surface coating composition which was liquefied by heating to a melting point (150° C. or 120° C.) of an amide compound, the copper plate was pulled up by taking 5 seconds and left for 10 minutes at a normal temperature thereby applying a thin film coating on the copper plate. The coating film was observed with naked eyes to evaluate the uniformity of the film. Those observed for nonuniformity due to cracking, creasing and separation were evaluated as failed (x) and those forming uniform film with no observation for any of the defects were evaluated as good (◯).

TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 High-consistency Lubricant base oil A 68 68 68 56 56 56 material Lubricant base oil B 56 56 56 56 56 56 56 68 49 50 56 50 Lubricant base oil C 56 Amide compound A 12 12 12 24 24 24 24 24 24 24 24 30 21 30 24 30 24 Amide compound B 24 24 Phosphorus OL-Ca 20 composition IS-Ca 20 20 IS-SA-Ca 20 20 20 20 20 20 20 20 20 20 2 30 20 20 20 20 Nucleating agent Talc (1.0 μm) 2 Talc (2.5 μm) 2 2 2 2 2 2 2 2 2 2 2 0.01 17.8 2 Talc (8.0 μm) 2 Kaolinite (1.5 μm) 2 Magnesium oxide 2 (10 μm) Montmorillonite 2 (0.3 μm) Coating property ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

TABLE 2 Comparative Example 1 2 3 4 5 6 High-consistency Lubricant base oil A 68 56 material Lubricant base oil B 56 68 70 70 Amide compound A 12 24 24 30 30 30 Amide compound B Phosphorus OL-Ca composition IS-Ca 20 IS-SA-Ca 20 20 2 Nucleating Talc (1.0 μm) agent Talc (2.5 μm) 2 Talc (8.0 μm) Kaolinite (1.5 μm) Magnesium oxide (10 μm) Montmorillonite (0.3 μm) Coating property X X X X X X

The metal surface coating compositions of Examples 1 to 19 showed sufficient coating property and the coated surfaces were uniform. On the contrary, since the metal surface coating compositions of Comparative Examples 1 to 4 did not contain the nucleating agent, cracking was observed after coating and the coated surface was not uniform. Further, since the metal surface coating compositions of Comparative Examples 5 to 6 did not contain the composition of the phosphorus compound and the metal, peeling occurred at the metal surface due to volumic change (shrinkage) of the high-consistency material caused by cooling after coating, and the coated surface was not uniform.

An embodiment of the present invention has been described specifically but the present invention is no way restricted to the embodiment described above but can be modified variously within a range not departing from the gist of the present invention.

It is to be understood that the foregoing is a description of one or more preferred exemplary embodiments of the invention. The invention is not limited to the particular embodiment(s) disclosed herein, but rather is defined solely by the claims below. Furthermore, the statements contained in the foregoing description relate to particular embodiments and are not to be construed as limitations on the scope of the invention or on the definition of terms used in the claims, except where a term or phrase is expressly defined above. Various other embodiments and various changes and modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. All such other embodiments, changes, and modifications are intended to come within the scope of the appended claims.

As used in this specification and claims, the terms “for example,” “e.g.,” “for instance,” “such as,” and “like,” and the verbs “comprising,” “having,” “including,” and their other verb forms, when used in conjunction with a listing of one or more components or other items, are each to be construed as open-ended, meaning that the listing is not to be considered as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation. 

1. A metal surface coating composition, comprising: a high-consistency material comprising a lubricant base oil and an amide compound, a composition of a phosphorus compound comprising one or more compounds represented by the general formulae (1) and (2) and a metal, and a nucleating agent,

where X¹ to X⁷ each represent independently an oxygen atom or a sulfur atom, R¹¹ to R¹³ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, among which at least one is a hydrocarbon group having 1 to 30 carbon atoms, and R¹⁴ to R¹⁶ each represent independently a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atom among which at least one is a hydrocarbon group having 1 to 30 carbon atoms.
 2. The metal surface coating composition according to claim 1, wherein the nucleating agent comprises an inorganic particle comprising a silicate or magnesia.
 3. The metal surface coating composition according to claim 1, wherein the nucleating agent comprises at least one of talc, kaolinite, montmorillonite, and magnesium oxide.
 4. The metal surface coating composition according to claim 1, wherein the nucleating agent has an average particle diameter of 20 μm or smaller.
 5. The metal surface coating composition according to claim 1, wherein the nucleating agent is contained at a content of 0.01 to 15 mass parts with respect to 100 mass parts of the total of the ingredients in the metal surface coating composition except the nucleating agent.
 6. The metal surface coating composition according to claim 1, wherein the composition of the phosphorus compound and the metal is made of at least one of a metal hydroxide and a metal carboxylate and the phosphorus compound.
 7. The metal surface coating composition according to claim 6, wherein the metal carboxylate is a metal salicylate.
 8. The metal surface coating composition according to claim 1, wherein the amide compound comprises one or more compounds represented by the following general formulae (3) to (5): [Chem. 3] R²¹—CO—NH—R²²  (3) [Chem. 4] R²³—CO—NH—Y³¹—NH—CO—R²⁴  (4) [Chem. 5] R²⁵—NH—CO—Y³²—CO—NH—R²⁶  (5) where R²¹ to R²⁶ each represent independently a saturated or unsaturated linear hydrocarbon group having 5 to 25 carbon atoms, R²² may be hydrogen, and Y³¹ and Y³² represent a divalent hydrocarbon group having 1 to 10 carbon atoms selected from an alkylene group and a phenylene group having 1 to 10 carbon atoms, or an alkylphenylene group having 7 to 10 carbon atoms.
 9. The metal surface coating composition according claim 1, wherein the amide compound is a fatty acid amide having a melting point within a range of 20° C. to 200° C.
 10. The metal surface coating composition according to claim 1, wherein the phosphorus compound has one or more branched linear structures or one or more carbon-carbon double bond structures in the structure of the hydrocarbon groups having 1 to 30 carbon atoms.
 11. The metal surface coating composition according to claim 1, wherein the metal forming the composition together with the phosphorus compound is at least one selected from alkali metals, alkaline earth metals, aluminum, titanium, and zinc.
 12. The metal surface coating composition according to claim 1, wherein the mass ratio of the total of the lubricant base oil and the amide compound to the composition of the phosphorus compound and the metal is within a range of 98:2 to 30:70.
 13. A terminal-fitted electric wire, wherein an electric connection part between a terminal and an electric conductor is covered with the metal surface coating composition according to claim
 1. 